It sounds like the start of a joke, but what’s the difference between taking Cornell’s CS6120 online and in-person? The instructor, [Adrian Samspon] notes that the real class has deadlines, an end-of-semester project, and a discussion board that is only open to real-life students. He also notes that you only earn “imagination credits.”
Still, this is a great opportunity to essentially audit a PhD-level computer science class on a fascinating topic. The course consists of videos, papers, and open source projects using LLVM and a custom internal representation based on JSON that is made for the class. It is all open source, too. You do however need access to the papers, some of which are behind paywalls. Your local library can help if you can’t otherwise find copies of the papers.
The newest Raspberry Pi 400 almost-all-in-one computer is very, very slick. Fitting in the size of a small portable keyboard, it’s got a Pi 4 processor of the 20% speedier 1.8 GHz variety, 4 GB of RAM, wireless, Ethernet, dual HDMI outputs, and even a 40-pin Raspberry Standard IDE-cable style header on the back. For $70 retail, it’s basically a steal, if it’s the kind of thing you’re looking for because it has $55 dollars worth of Raspberry Pi 4 inside.
In some sense, it’s getting dangerously close to fulfilling the Raspberry Pi Dream. (And it’s got one more trick up it’s sleeve in the form of a huge chunk of aluminum heat-sinked to the CPU that makes us think “overclocking”.)
We remember the founding dream of the Raspberry Pi as if it were just about a decade ago: to build a computer cheap enough that it would be within everyone’s reach, so that every school kid could have one, bringing us into a world of global computer literacy. That’s a damn big goal, and while they succeeded on the first count early on, putting together a $35 single-board computer, the gigantic second part of that master plan is still a work in progress. As ubiquitous as the Raspberry Pi is in our circles, it’s still got a ways to go with the general population.
The Raspberry Pi Model B wasn’t, and isn’t, exactly something that you’d show to my father-in-law without him asking incredulously “That’s a computer?!”. It was a green PCB, and you had to rig up your own beefy 5 V power supply, figure out some kind of enclosure, scrounge up a keyboard and mouse, add in a monitor, and only then did you have a computer. We’ve asked the question a couple of times, can the newest Raspberry Pi 4B be used as a daily-driver desktop, and answered that in the affirmative, certainly in terms of it having adequate performance.
But powerful doesn’t necessarily mean accessible. If you want to build your own cyberdeck, put together an arcade box, screw a computer into the underside of your workbench, or stack together Pi Hats and mount the whole thing on your autonomous vehicle testbed, the Raspberry Pi is just the ticket. But that’s the computer for the Hackaday crowd, not the computer for everybody. It’s just a little bit too involved.
The Raspberry Pi 400, in contrast, is a sleek piece of design. Sure, you still need a power supply, monitor, and mouse, but it’s a lot more of a stand-alone computer than the Pi Model B. It’s made of high-quality plastic, with a decent keyboard. It’s small, it’s light, and frankly, it’s sexy. It’s the kind of thing that would pass the father-in-law test, and we’d suggest that might go a long way toward actually realizing the dream of cheaply available universal (open source) computing. In some sense, it’s the least Hackaday Raspberry Pi. But that’s not saying that you might not want one to slip into your toolbag.
If you thought your home-brew project was taking a long time, [Jeroen Brinkman]’s MERCIA Relay Computer project probably has you beat. He began working on this impressive computer back in 2014, and has been at it ever since. In fact, the ongoing nature of the project is embedded into the name itself — the English translation of the acronym MERCIA is “My Simple Relay Computer Under Construction”. Being interested in old analog and relay computers from an early age, [Jeroen] took on this project to educate students about how computers work. The entire computer is build only using relays, diodes, and capacitors, not to mention color-coded wire based on signal functions. Using relays as the primary switching elements is at the core of his educational goal — anyone can understand how a relay works.
Understandably, this thing is big. But he has cleverly packaged it to visually show the major building blocks of a computer. While the exact size isn’t stated, we can estimate based on the photo of [Jeroen] standing next to the modules that these panels are about 1.5 m tall and perhaps 60 cm wide. The whole computer is nine panels wide, making it about 5 meters long. Except for the ROM assembly, pairs of panels are hinged together and they fold like a book and carried like a suitcases when being moved. If you enjoy the clickety-clack sound of relays, be sure to watch the relay longevity test in the video below and check out our article on the 1958 FACOM from last year.
This is a fascinating project, but unless you have a couple thousand relays laying around and a decade of free time, it’s probably better to just enjoy [Jeroen]’s work rather than build your own. We hope he releases schematics and other documentation once the project is finished. You can follow his Facebook build log if you want to keep track of the progress. Thanks to [David Gustafik] for the tip.
There’s an old tale that TV companies only need to make a few years of kids’ TV shows, because their audience constantly grows out of their offerings and is replaced by a new set with no prior knowledge of the old shows. Whether it’s true or not is up for debate, but does the same apply to single board computers aimed at kids? The original BBC micro:bit was first announced back in 2015 and must be interesting its second generation of kids by now, but that hasn’t stopped them bringing out a second version of the little educational computer. How do you update such a simple device? Time to take a look.
Edge connector shown on the original micro:bit design
The form factor of the new board is substantially the same as its predecessor, with the same edge connector and large connection pads, and the familiar LED matrix display. The most obvious additions are a small speaker and MEMS microphone allowing kids to interact with audio in their code, but less obvious is a new touch button in the micro:bit logo. The original had it in the silk screen layer, while the new one has it as copper for a capacitive sensor.
The silicon has an upgrade too, now sporting a Nordic Semiconductor nRF52833 running at 64 MHz and sporting 512k of ROM and 128k of RAM with built-in Bluetooth Low Energy. Binaries are incompatible with the original, however all the development environments can recompile code for a new universal binary format capable of running the appropriate software for either version.
The micro:bit has been more of a hit in schools than it has in our community, perhaps because it has the misfortune to have arrived alongside so many strong competitors. However it remains a powerful contender whose easy programming alongside the power of more traditional toolchains make it a good choice for kids and grown-ups alike. We took a look at the original back in 2016, if you are interested.
After seeing the poorly embossed paper maps used in the school, [Sergei] decided there had to be a better way. The solution was 3D printing, which makes producing a map with physical contours easy. Initial attempts involved printing street maps and world maps with raised features, such that students could feel the lines rather than seeing them.
Taking things a step further, [Sergei] went all out, producing an interactive educational device. The build consists of a world map, and contains audio files with information about countries, cultures, and more. When the ultrasonic sensor detects a user in range, it invites them to press or pull out the removable continents on the map. The device can sense touch, thanks to a pair of MPR121 capacitive touch sensor boards which are used to trigger the audio files.
When you think of iRobot, you probably think of floor cleaning or military robots. But they also have a set of robots aimed at education. The Root robot — an acquisition the company made in 2019 — originally targeted classrooms and cost about $200 each. A new version costs about $130 and is a better fit for home users.
The original version — Root rt1 — is still available, but the rt0 version has several missing features to hit the desired price. What’s missing? Apparently, the rt1 can stick to a whiteboard using magnets, but that feature is missing on the rt0. There are also no “cliff” sensors or color scanner.
The global COVID-19 pandemic has kept many of us socially isolated from friends, family, and colleagues for several months at this point. But thanks to modern technology, the separation has only been in the physical sense. From job interviews to grade school book reports, many of the things we’d previously done in person are now happening online. The social distancing campaign has also shown that virtual meetups can be a viable alternative to traditional events, with several notable hacker conventions already making the leap into cyberspace.
With this in mind, we’re proud to announce HackadayU. With weekly online videos and live office hours, these online classes will help you make the most of your time in isolation by learning new skills or diving deeper into subjects with experienced instructors from all over the world. Whether you’re just curious about a topic or want to use these classes to help put yourself on a new career path, we’re here to help.
In a community like ours, where so many people already rely on self-study and tutorial videos, these four week classes are perfect for professional engineers and hobbyists alike. To make sure HackadayU is inclusive as possible, classes will be offered on a pay-as-you-wish basis: we’ll pick up the tab for the instructor’s time, and you kick in whatever you think is fair. All money collected will be donated to charities that help feed, house, and educate others. We know these are tough times, and the hope is that HackadayU can not only benefit the members of our core community, but pass on some goodwill to those who are struggling.
After seeing the poorly embossed paper maps used in the school, [Sergei] decided there had to be a better way. The solution was 3D printing, which makes producing a map with physical contours easy. Initial attempts involved printing street maps and world maps with raised features, such that students could feel the lines rather than seeing them.
